Abstract

Background

Cholinesterase inhibitors (ChEIs) such as donepezil have the effect of delaying progression
of Alzheimer’s disease (AD), but their effect on life expectancy is unclear. We analyzed
the influence of donepezil on life expectancy after onset of AD, together with the
effects of antipsychotic drugs and residency in a nursing home.

Methods

All outpatients at the Tajiri Clinic from 1999–2012 with available medical records
and death certificates were included in a retrospective analysis. The entry criteria
were a dementia diagnosis based on DSM-IV criteria and diagnosis of AD using NINCDS-ADRDA
criteria; medical treatment for more than 3 months; and follow up until less than
1 year before death.

Results

We identified 390 subjects with medical records and death certificates, of whom 275
had a diagnosis of dementia that met the entry criteria. Of 100 patients diagnosed
with AD, 52 had taken donepezil and 48 patients had not received the drug due to treatment
prior to the introduction of donepezil in 1999 in Japan. The lifetime expectancies
after onset were 7.9 years in the donepezil group and 5.3 years in the non-donepezil
group. There was a significant drug effect with a significant covariate effect of
nursing home residency. Other covariates did not reach a significant level.

Conclusions

Although this report has the limitation of all retrospective analyses: the lack of
randomization, we found a positive effect of donepezil on lifetime expectancy after
onset of AD. This may be due to a decreased mortality rate caused by reduction of
concomitant diseases such as pneumonia. The similar life expectancies in patients
taking donepezil at home and those not taking donepezil in a nursing home indicated
a positive health economic effect of the drug.